The present invention relates, in general, to a bending device for tubular pipes or like members.
Nothing in the following discussion of the state of the art is to be construed as an admission of prior art.
German utility model no. DE 201 18 444 U1 describes a bending device having a bending tool to bend a tubular member. As the inner region of the tubular member to be bent is exposed to significant pressure stress, there is a tendency in the tube wall to form wrinkles. In order to prevent wrinkling in the surface of the tubular member, a wiper die is positioned near the bending tool. As a result, wrinkling can be avoided so long as the wiper die is correctly positioned relative to the bending tool. The wiper die has hereby a receiving channel which merged tangentially into a circumferential recess of the bending tool. The presence of just a small unevenness or air gap between the bending tool and the wiper die is however sufficient to cause wrinkling and furrows, thereby considerably impairing the quality of the bent tubular member. The wiper die is also adjustably constructed to account for wear during use. Still, the wiper die must be completely replaced when worn out and undertaking a certain number of bending processes.
It would be desirable and advantageous to provide an improved bending device to obviate prior art shortcomings.